What is "noldor"

In the works of J. R. R. Tolkien, the Noldor (also spelled Ñoldor, meaning those with knowledge in Quenya) are Elves of the Second Clan who migrated to Valinor and lived in Eldamar. The Noldor are called Golodhrim or Gódhellim in Sindarin, and Goldui by Teleri of Tol Eressëa. The singular form of the Quenya noun is Noldo and the adjective is Noldorin. They were the Second Clan of the Elves in both order and size, the other clans being the Vanyar and the Teleri. Like the Teleri, they typically had grey eyes and dark hair (except for those who had Vanyarin blood, most prominently the members of the House of Finarfin).